Yes, except no. Unless he's talking Jupiter years or something (which he might be, it's a Doctor-y thing to do). McCoy's Doctor was 953 Gallifreyan years at the START of his regeneration. He lived long enough to start ageing, which we know from Matt Smith's Doctor takes well over 300 years (let's call it 347 for lazy…

My hypothesis: he burns through regeneration energy to stop the ageing (thus the comment when he first travels to Pete's world that he "just took ten years off my life" to recharge the TARDIS, also River's comment about "taking the age down a little"). Once he gets low, he starts to get older like a normal Gallifreyan…