If a child or person with disabilities is not accountable (does not know right from wrong and will not be able to repent and live up to the covenants (promises) made at baptism that the person will not be baptized.
This is a collection of church quotes that reference this topic.
We first need to establish that within church lingo that a person with disabilities that is deemed not accountable is the same as when a leader says "infant baptism" or "infant death" which is the same as baptizing children under the age of 8 or children passing away under the age of 8. They are all interchangeable.
Ensign April 1976 "Should Mentally Retarded Children be Baptized?" by Josiah Douglas
(please note that this article uses language appropriate from the time period such as "retarded")
The whole article is good and you should read it, here is a quote from it...
The Prophet Joseph Smith described the condition of children who die and have not reached the age of accountability. “And I also beheld that all children who die before they arrive at the years of accountability are saved in the Celestial Kingdom of Heaven.” (History of The Church of Jesus Christ of Latter-day Saints, 2:381.) Temple ordinances for mentally retarded persons who are deceased, however, are performed on the same basis as they are for any deceased person—without consideration of mental retardation.
General Conference Oct 2012 "Because I live, ye shall live also" by Elder Shayne M. Bowen
Prophet Joseph Smith, ...taught this comforting doctrine: “The Lord takes many away, even in infancy, that they may escape the envy of man, and the sorrows and evils of this present world; they were too pure, too lovely, to live on earth; therefore, if rightly considered, instead of mourning we have reason to rejoice as they are delivered from evil, and we shall soon have them again.”
Gospel Principles Manual Chapter 20 Page 117 (bold and underline added by the blog author)
Baptism at the Age of Accountability
Who should be baptized?
Every person who has reached eight years of age and is accountable (responsible) for his or her actions should be baptized. Some churches teach that little children should be baptized. This is not in keeping with the teachings of the Savior. When Jesus spoke of little children, He said, “Of such is the kingdom of heaven” (Matthew 19:14).
The prophet Mormon said that it is mockery before God to baptize little children, because they are not capable of sinning. Likewise, baptism is not required of people who are mentally incapable of knowing right and wrong (see Moroni 8:9–22). All other people are to be baptized. We must receive the ordinance of baptism and remain true to the covenants we make at that time.
Ensign Apr 1977 "The Salvation of Little Children" by Bruce R. McConkie
Note from Blog Author...Joseph F. Smith had 9 of his own children die. If you read 1 link I post here, have it be this one. This is a fantastic talk.
Teachings of Presidents of the Church: Joseph F. Smith Chapter 15
Note from Blog Author...Joseph F. Smith had 9 of his own children die. This whole chapter is excellent. You should really read the entire talk! There is too much excellent information to copy and paste it here.
Gospel Topics: Baptism
From latter-day revelation, we know that little children are redeemed through the mercy of Jesus Christ. The Lord said, “They cannot sin, for power is not given unto Satan to tempt little children, until they begin to become accountable before me” (see Doctrine and Covenants 29:46–47). They are not to be baptized until they reach the age of accountability, which the Lord has revealed to be eight years of age (see Doctrine and Covenants 68:27; Joseph Smith Translation, Genesis 17:11). Anyone who claims that little children need baptism “denieth the mercies of Christ, and setteth at naught the atonement of him and the power of his redemption” (Moroni 8:20; see also verses 8–19, 21–24).
From latter-day revelation, we know that little children are redeemed through the mercy of Jesus Christ. The Lord said, “They cannot sin, for power is not given unto Satan to tempt little children, until they begin to become accountable before me” (see Doctrine and Covenants 29:46–47). They are not to be baptized until they reach the age of accountability, which the Lord has revealed to be eight years of age (see Doctrine and Covenants 68:27; Joseph Smith Translation, Genesis 17:11). Anyone who claims that little children need baptism “denieth the mercies of Christ, and setteth at naught the atonement of him and the power of his redemption” (Moroni 8:20; see also verses 8–19, 21–24).
Handbook 2 section 20.1 (Bolding added by Blog author)
The ordinances of baptism, confirmation, Melchizedek Priesthood ordination (for men), the temple endowment, and temple sealing are required for exaltation for all accountable persons.
Bible Dictionary: Baptism
The age at which baptism should be administered is not specified in the Bible, although it is evident that candidates were to be old enough to be capable of belief and have some understanding. In latter-day revelation we learn that the Lord has set the age at eight years as the time when a person begins to become accountable and can be baptized (D&C 20:71; 68:25–28). This was also the age given in Old Testament times (JST Gen. 17:11 [Appendix]).
As members of the Lord’s restored Church, we are blessed both by our initial cleansing from sin associated with baptism and by the potential for an ongoing cleansing from sin made possible through the companionship and power of the Holy Ghost—even the third member of the Godhead.
(Note from blog author which are my own thoughts: Children with disabilities who are unaccountable do not need the initial cleansing from sin, or the ongoing cleansing from sin...they are not accountable.)
The Prophet Joseph Smith explained that “baptism is a holy ordinance preparatory to the reception of the Holy Ghost; it is the channel and key by which the Holy Ghost will be administered. The Gift of the Holy Ghost by the laying on of hands, cannot be received through the medium of any other principle than the principle of righteousness” (Teachings: Joseph Smith, 95–96).
(Note from Blog Author which are my own thoughts: We lose the holy ghost through sinning. People who are unaccountable do not sin. So they do not need the channel/key/medium to open the way for the Holy Ghost.)
These four words—“Receive the Holy Ghost”—are not a passive pronouncement; rather, they constitute a priesthood injunction—an authoritative admonition to act and not simply to be acted upon (see 2 Nephi 2:26). The Holy Ghost does not become operative in our lives merely because hands are placed upon our heads and those four important words are spoken. As we receive this ordinance, each of us accepts a sacred and ongoing responsibility to desire, to seek, to work, and to so live that we indeed “receive the Holy Ghost” and its attendant spiritual gifts. “For what doth it profit a man if a gift is bestowed upon him, and he receive not the gift? Behold, he rejoices not in that which is given unto him, neither rejoices in him who is the giver of the gift” (D&C 88:33).
(Note from Blog Author which are my own thoughts: Someone who is unaccountable cannot do these actions, so they would just "have those four words spoken" but not be able to take the "actions". Since they would not be able to "receive the gift" they would not rejoice in that which was given, or in the giver of the gift (Christ).)
8 aListen to the words of Christ, your Redeemer, your Lord and your God. Behold, I came into the world not to call the righteous but sinners to repentance; the bwhole need no physician, but they that are sick; wherefore, little cchildren are dwhole, for they are not capable of committing esin; wherefore the curse of fAdam is taken from them in me, that it hath no power over them...
9 ... it is solemn amockery before God, that ye should baptize little children.
10 Behold I say unto you that this thing shall ye teach—repentance and baptism unto those who are aaccountable and capable of committing sin...
11 And their little achildren need no repentance, neither baptism. Behold, baptism is unto repentance to the fulfilling the commandments unto the bremission of sins.
12 But little achildren are alive in Christ, even from the foundation of the world; if not so, God is a partial God, and also a changeable God, and a brespecter to persons; for how many little children have died without baptism!
13 Wherefore, if little children could not be saved without baptism, these must have gone to an endless hell.
14 Behold I say unto you, that he that supposeth that little children need baptism is in the gall of bitterness and in the bonds of iniquity; for he hath neither afaith, hope, nor charity; wherefore, should he be cut off while in the thought, he must go down to hell.
15 For awful is the wickedness to suppose that God saveth one child because of baptism, and the other must perish because he hath no baptism.
17 And I am filled with acharity, which is everlasting love; wherefore, all children are alike unto me; wherefore, I love little children with a perfect love; and they are all alike and bpartakers of salvation.
18 For I know that God is not a partial God, neither a changeable being; but he is aunchangeable from ball eternity to all eternity.
19 Little achildren cannot repent; wherefore, it is awful wickedness to deny the pure mercies of God unto them, for they are all alive in him because of his bmercy.
20 And he that saith that little children need baptism denieth the mercies of Christ, and setteth at naught the aatonement of him and the power of his redemption.
22 For behold that all little children are aalive in Christ, and also all they that are without the blaw. For the power of credemption cometh on all them that have dno law; wherefore, he that is not condemned, or he that is under no condemnation, cannot repent; and unto such baptism availeth nothing—
23 But it is mockery before God, denying the mercies of Christ, and the power of his Holy Spirit, and putting trust in adead works.
24 Behold, my son, this thing ought not to be; for arepentance is unto them that are under condemnation and under the curse of a broken law.
And it came to pass that he said unto them: Behold, here are the waters of Mormon (for thus were they called) and now, as ye are adesirous to come into the bfold of God, and to be called his people, and are willing to bear one another’s burdens, that they may be light;
9 Yea, and are awilling to mourn with those that bmourn; yea, and comfort those that stand in need of comfort, and to stand as cwitnesses of God at all times and in all things, and in all places that ye may be in, even until death, that ye may be redeemed of God, and be numbered with those of the dfirst resurrection, that ye may have eternal life
(Note from Blog Author which are my own thoughts: People who are found unaccountable are also typically unable to bear one anothers burdens, mourn with those that mourn, etc...)
Other scriptures about accountability are listed here