I know it’s already been commented on, but:
There is NO excuse for this. I’m the biggest grammar Nazi I know, but I can’t IMAGINE saying that some piece of slang primarily identified with a region or culture or color stems ONLY from “stupidity and laziness”. You have got to be kidding. Go ahead and take the next step, and say that the American “Black accent” just shows how they’re all lazy and dumb.
C’mon, royjwood. Say it. I want to hear you say “my bad”!
I started hearing and using this at the age of 12 (in 1987) when playing pick-up games on courts in downtown Denver. It went well with other phrases/words such as face, toast, and ball up. Ahh, the mis-spent days of my grammar impaired youth.
Since the question seems to have been answered, I’ll just hijack a bit. I grew up in the seventies, and in street basketball games, if someone was fouled, he would inevitably cry, “I got the foul!”, and point at the offending player. What did you use?
I don’t believe it has anything to do with being stupid or lazyness. I mean, if you really wanted to play that card, who’s really smarter?
The guy who uses 10 words to state or describe something, or the guy that uses 3, 4, or 5 words to describe the same exact thing.
Using less words is more efficient and quicker. Know what I sayin’ G?
This? “I’m so terribly sorry, my fault.”
Or, “My Bad.”
They both have the same meaning.
This isn’t your great grandfathers english anymore.
I generally like slang, but this one has always grated on me. Now I know why—it comes from basketball, and I hate sports!
whoooooooooooooooooooosh!
Same meaning but that doesn’t mean it’s a translation.
(BTW speaking of grammar, can one “be being” something?)
I may be being awkward in my choice of words, but I don’t believe that I am being ungrammatical in doing so. 
I could write in E-prime if you prefer.
Just want to verify the origin. Back in the mid 80’s a friend of mine went away to Basketball Camp for a few weeks. When he returned to play pick up games with us he started using “my bad” when he messed up. We all looked at him like there was something wrong. We all know it was a blatant error in grammar and didn’t know why he kept saying it.
Obviously he explained that he picked up the term at camp. We would use it in a joking way because it sounded stupid. There then came a time when we realized we had incorporated it into our every day “hang out” vocabulary.
I never realized it still was being used today. Can you imagine people using “boss”, “fly” and “keen” today? They were terms from certain times and sound so dated. “My bad” must have stood the test of time but to me it sounds so 80’s.
What I find funny is that it took 15 years to hit mainstream American slang. Was it considered dead until Clueless used it in the movie?
Eve said:
That’s OK, everyone has to have 1 flaw.
The biggest bonus of being a white guy that plays regularly in pick-up games in some rather seedy areas is that I always secretly understand the slang that some of my darker complected brothers and sisters use when they think I don’t have a clue what they are saying. Very handy.
I agree. The OP was definitely of basketball origin, and quite useful, as some have pointed out.
We always said, “That’s mine” or “I’ll take that” or “my ball” to indicate that play should stop because a foul had been committed.
I won’t even mention “No Fly Zone” in Milspeak. Maybe we should update it to “Your Bad Zone”
Heh, I use “boss” and “keen” all the time, depending on what I’m describing. “Boss” if I’m admiring someone’s “cherry” Mustang and “keen” if I’m admiring someone’s “swell” new saddle shoes. In a few years I’m sure I’ll be saying “awesome!” to someone’s “totally rad” retro '80’s Flock of Seagulls Haircut.
Re: “My bad,” I just always assumed it was short for “my bad grammar.” (JOKE!)
I still use “spiffy.”
Does that make me a bad person?
Unortunately you only qualify as a person and not people. 
I’ve noticed this too. “Be” seems to have changed to where it’s not simply a state of being verb - not always indicative:
BE careful.
Don’t BE stupid.
BE nice.
Seems it has become, in some usage, transitive. Telling somebody to BE careful implies that it is something they DO, not something they ARE.
But, isn’t “my bad” out now? Totally lame? Gone the way of the dodo?
I haven’t heard it in years. I guess I’m just not with it anymore. I heard skater boys (who seem to have come back from whatever migration they went on a few years ago) say something was “sick” a while ago, in a positive sense. That was a new one for me.
Okay. Fall, 1969. I was in Tennessee during my freshman year in college. I grew up in Atlanta, and had never heard the term “my bad” in my life. My roomate my freshman year (who, incidentally, was white and had never played basketball) was from Birmingham, Alabama and said “my bad” frequently to mean my fault or my mistake. As I met other people from Birmingham, I also noticed them saying “my bad.” I didn’t notice people from Mobile or Montgomery saying it, and I didn’t notice people from Nashville or Memphis saying it. Just people from Birmingham.
Now, I have no idea what this tells us about the origin of the term. But I do know that it’s been around a lot longer than the mid 80’s, at least in Birmningham.
A neologism is a completely new word or completely new usage of an existing word.